What does code P289B mean?

Q: What does code P289B mean?

Cylinder 3 Ion Current Sense Circuit High. P289B indicates that the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 3, which is used to monitor combustion quality. The ECM expects the ion current signal to stay within a specific voltage range, and a high reading suggests a short to voltage, an open circuit, or a faulty sensor.

DTC codes / P28xx · Transmission / P289B

P289BCylinder 3 Ion Current Sense Circuit High

P289B indicates that the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 3, which is used to monitor combustion quality. The ECM expects the ion current signal to stay within a specific voltage range, and a high reading suggests a short to voltage, an open circuit, or a faulty sensor.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.